Functionalized Carbon-Based Composite Materials for Cathode Application of Lithium-Sulfur Batteries

Carbon-based materials exhibit excellent physical and chemical properties due to their diverse structure, adjustable morphology and controllable composition. They have great application potentials in the field of new energy storage and conversion. Lithium-sulfur batteries as a kind of important new energy storage devices are trapped by the sulfur and lithium sulfide bottleneck of electronic insulation, which leads to irreversible charging and discharging processes. Fortunately, carbon-based composite materials have strong electrical conductivity. The coupling of multi-functions of the composite materials can improve the long-term utilization of sulfur and alleviate the attenuation of cycle and rate capacity. Functionalized carbon-based composite materials can be prepared through surface/interface and defect engineering techniques, which have attracted the attention and favor of scientific researchers. We review the preparation methods of functionalized carbon-based host materials and analyze the structure-function relationship of carbon-based composite materials and sulfur cathodes. We discuss the influence of the change of morphology, structure, and composition on the electrochemical performance of sulfur cathode. Finally, the feasibility of the functionalized carbon-based composite materials are prospected in the practical application of the lithium-sulfur battery.